There are many processes that require a form of fluid conditioning in chemical processing plants, oil refineries, factories, food processing, farm and animal byproduct processing, wastewater treatment, solid waste treatment, and the like. As these aforementioned processes are usually necessarily for our modern economy, technology is usually applied to control the undesirable environmental contaminates generated from the previously mentioned processes for a number of reasons, with these contaminants being in gaseous form, in liquid form, or in solid form. These reasons would include reduction of physical pollutants, reduction of visible pollutants, reduction of odorous contaminants, reduction of chemical contaminants, and the like. As the concern for the environment continues to increase it becomes ever more important to control these contaminants to lower and lower acceptable levels.
This issue of industrial process contaminant control has been fairly well recognized in the prior art with a number of apparatus designed for contaminant treatment that include conventional filtering systems, and other more technologically adept systems such as scrubbers that are typically used with a contaminated gas stream, wherein a chemical is introduced into the gas stream to bond with an undesirable contaminant in the gas stream, wherein the bonding results in typically a new solid being formed that can precipitate out of the gas stream due to its higher density allowing for separation of the contaminant out of the gas stream. Another prior art gas contaminant process involves what is called electrostatic precipitation, wherein the suspended contaminants are ionized, with the ionized contaminants being attracted to an electrode, thus enabling the separation of the contaminants from the gas stream. However, all of the aforementioned systems have limitations, such as conventional filtering not having the ability to remove very small contaminants or well dispersed contaminants, plus temperature and pressure limitations, along with high maintenance, i.e. filter cleaning/replacement required. Further, scrubbers are limited by needing to be used with a closed loop system, i.e. contained within a series of enclosures separated from the outside environment, which precludes open type systems such as some wastewater and solid waste treatment processes, in addition scrubbers require that the contaminant be able to bond with an introduced chemical with and form some sort of matter having a density higher than the gas being treated to allow separation of the contaminate from the gas being treated. In addition, for electrostatic precipitators, much the same as for scrubbers a closed loop system would be required as previously discussed and there would be the need for the contaminate to be ionizable to facilitate the electrostatic attraction of the contaminate out of the polluted gas stream.
Another type of fluid decontamination is with the use of introducing a desirable odor containing fluid to mask or cover-up an undesirable odor, thus not having the requirements of using the closed loop system as previously described nor that the contaminant have some sort of special properties to enable the separation of the contaminant from the polluted gas for instance. However, this introduction of a cover-up type of chemical has drawbacks in control over the system that is being decontaminated as the actual removal or neutralization of contaminates is not necessarily known, at least making the cover-up type of chemical fluid decontamination apparatus less desirable when used in conjunction with the open type system because of this lack of control as previously discussed. Also, because of the random interaction of the desirable odor containing fluid with the polluted gas, there is the ongoing problem of insufficient atomization of the introduced odor containing fluid within the polluted gas, thus the prior art has recognized this issue and has developed several structures to help improve atomization of the introduced fluid being dispersed within the polluted gas for more efficient odor control and less waste of the non atomized introduced fluid.
As a prior art example in addressing the need for improved atomization of the introduced fluid, in U.S. Pat. No. 6,770,247 B1 to Romack et al., disclosed is a liquid product vaporizing apparatus for an air deodorizing system comprising an inlet channel, a vaporization chamber, an air blower, and distribution pipes. In Romack et al., fresh air is drawn into the system through the inlet channel by the air blower, creating a stream of air flowing through the system. The stream of air in Romack et al., is directed to the vaporization chamber where an atomizing nozzle sprays atomized liquid product into the vaporization chamber. The treated air stream in Romack et al., then flows through distribution pipes to a plurality of vapor release ports which allow the treated air to be released into the malodorous area, reference column 3, lines 12-25. The main issues in Romack et al., are that the chamber configuration has no internal obstructions between the inlet and outlet ports; also it is utilized in an open system, i.e. taking in ambient air for the Romack et al., inlet being in not being from a closed system. In addition, Romack et al., does not teach the use of a control system for achieving a selected an odor reduction level or the ability to maintain an odor level, furthermore Romack et al., does not address use in hazardous environments, i.e. explosive gases being present and the like.
A further prior art example for a conventional air freshener (not being a scrubber or electrostatic precipitator) is in U.S. Pat. No. 6,435,419 to Davis that discloses a liquid air freshener dispensing device for a building ventilation duct being removably attachable to the duct, wherein the entire Davis system would be considered an open loop system as the building volumetric portion is not sealed. In Davis, the duct is in communication with a heating member and a blowing member, wherein the blowing member blows air across the heating member and into the duct including a coalescing filter to help prevent the air freshener droplets from collecting on the plenum walls as a method to further help the recognized problem of adequate atomization of the deodorant liquid in the gas plenum. Again in Davis, there is no teaching related to a control system for monitoring deodorant use and effective odor control in the building air volume nor use in hazardous (explosive or toxic) environments. Similar to Davis in U.S. Pat. No. 5,302,359 to Nowatzki is an apparatus used for building duct ventilation systems that is a self contained unit that utilizes a reservoir, a pump, and a dispenser for dispersing the liquid deodorant with a switch that resides on top of the ventilation duct. Nowatzki also has no disclosure related to a control system for sensing the odor levels and adjusting the amount of deodorizing fluid input.
In addition, also similar to Davis and Nowatzki, in being an air deodorizer for building type applications, in U.S. Pat. No. 5,030,253 to Tokuhiro et al., disclosed is a fragrant air supply system by using a mist generating means by either air velocity of ultrasonic means. In Tokuhiro et al., the purpose is to add fragrance, rather that remove contaminants, Tokuhiro et al., does have the features of a controller for measuring the concentration of fragrance, see FIGS. 6 and 7, wherein the controller regulates the flow of the fragrance liquid and air flow into the chamber based upon the measured concentration of the fragrance. Also, included in Tokuhiro et al., is a chamber drain to recycle liquid fragrance into the liquid fragrance reservoir that is caught by the end face 41 that removes un-evaporated mist from the fragranced air. As Tokuhiro et al., is an open loop system in that only the output concentration of fragranced air is measured and controlled as the fragranced air is sent to the building interior, with no feedback or return of air possible for recycling into the system, thus the only control is for the detection and non-detection of fragranced air within the building, again see FIGS. 6 and 7. A similar type apparatus again for deodorizing, utilizing chlorite compounds is disclosed in U.S. Pat. No. 5,989,497 to Labonte Jr. that teaches a process and apparatus for deodorizing malodorous substances with specifically a chlorine dioxide-containing composition. The apparatus in Labonte, Jr., comprises a reservoir for supplying a concentrated deodorizing liquid, a means for supplying water for diluting the aqueous deodorizing liquid, an eductor for mixing the dilution water supplied and the deodorizing liquid supplied, a means for controlling the amount of the deodorizing solution, and a plurality of spray nozzles for spraying the deodorizing solution, reference column 2, lines 37-46. Note that Labonte, Jr., is also an open system primarily designed for sewers, solid waste dumps, landfills, waste lagoons, and the like. Labonte, Jr., does have some mention of a control system via the use of a monitor to detect for instance the level of hydrogen sulfite on whether to continue or stop the system and to select the amount of deodorizing liquid to be used, i.e. being a higher or lower flowrate. Further, note that Labonte, Jr., does not address use in explosive or toxic environments.
Continuing, in looking at a typical prior art scrubber as shown in U.S. Pat. No. 4,844,874 to deVries disclosed is a method and means for controlling a mist scrubbing process in which a gas containing odorous and acidic contaminants are contacted in a reaction chamber with tiny droplets of an aqueous reagent to react with and destroy the contaminants. In deVries, although this is an open system also, however, having monitoring based on measuring chemical properties of the spent contaminated mist and scrubbed gas output. Specifically, in deVries the control system measures pH of the spent stray liquid settling at the bottom of the chamber to control the flow of a “base” chemically speaking, with this being in addition to a measurement of the acidic component of the scrubbed gas leaving the reaction chamber to control the rate at which an oxidizing agent is injected into the system. As previously discussed in scrubber systems such as deVries, there is little concern for complete atomization of the injected mist solution as there is expected to be residual liquid mist solution at the bottom of the chamber that is used to ensure bonding with the with the contaminants, i.e. more mist is available than contaminants need to bond with, in an attempt to have more complete scrubbing, in conjunction with the injected mist having a “once through” application in its potential bonding contact with the gas contaminants and is not recycled, however, as stated previously the residual mist solution is measured for pH.
Further, in looking at the prior art in this area for another open system that generates an open mist of decontaminant, reference U.S. Pat. No. 7,008,592 to Sias et al. wherein disclosed is a decontamination apparatus method using an activated cleaning fluid mist for decontamination of environments and open or exposed articles from microbiological organisms. The Sias et al., apparatus comprises a cleaning fluid, a mist generator having an input flow of the cleaning fluid and an output flow of a mist of the cleaning fluid that contains ions, from an activator to activate the cleaning fluid mist that is operational to help increase efficiency of the decontamination process by the activated decontaminant entering into a redox reaction with the microbiological contaminant, reference column 1, lines 62-64, column 2, lines 20-26, and column 5, lines 50-60. Next, in U.S. Pat. No. 6,548,025 B1 to Rasouli et al., disclosed is another open loop odor generator utilizing a disc with a porous substrate having a releasable aroma that reacts to a control system signal that allows a variety of scents to be disbursed from a single disc thereby allowing a computer connected to the internet to send a signal to the odor generator to generate a selected scent from a remote location. Thus in Rasouli et al., per se the control is not for overcoming a contaminant, however, being for a selected scent sampling from a remote location.
Continuing, in U.S. Pat. No. 5,380,498 to Kuivalainen disclosed is an apparatus for the purification of waste gases that includes the use of reagents or absorbent, wherein a “wet” zone recycles the wetting zone particles that have been separated from the from the gas outside of the wetting zone chamber by first introducing the contaminated gases into the wetted zone of the chamber with the absorbent or reagent in suspension. Wherein in Kuivalainen, next the wet chamber mixture of the contaminated gas and absorbents and reagents moves to a dry chamber portion to dry the wetted particles from the wet zone with the goal being to re-carry the particles that are unreacted back into the wet zone to increase the efficiency of the reaction process. There is no teaching in Kuivalainen related to an active control system to regulate the amount of transition between the wet and dry zones or the amount of absorbents or reagents to introduce into the system, there is some specific test data related to empirical reactions using the apparatus, however, no ongoing control of the process is disclosed.
In addressing another area, in U.S. Pat. No. 4,963,330 to Johansson et al., disclosed in a method and apparatus for treating contaminated gasses having a multi medium nozzle that allows multiple fluids to be used in a single nozzle, that can be utilized for multiple chemical injections simultaneously or if desired using one of the nozzle fluid feeds to act as a cleaning agent for the nozzle that has undesirable deposits from another injected fluid.
What is needed is a fluid conditioning apparatus that is operable for the control of a closed loop system having feedback on contamination levels for a process with the ability to adjust the fluid injection rate and/or process fluid treatment flowrates to control the process contamination levels to a selected level, in addition with the capability for the fluid conditioning apparatus to be operable in hazardous or toxic environments, either for the closed loop process itself or the external environment that the fluid conditioning apparatus is in. Thus, the fluid conditioning apparatus could have the ability to operate in an intrinsically safe manner with the controls in place to set the amount of fluid injected, timing intervals for fluid injection, and have a mechanism to motivate the system fluid to be conditioned at a selected flowrate until a selected de contamination level is reached for the associated process. Further, it would be desirable to provide for removal of a portion of the un-atomized fluid injection from the process fluid stream to ensure a higher efficiency of the fluid injection de-contaminating the process in a shorter time period. In addition, the fluid conditioning apparatus should be skidded as a unit including the control system for potential portability to be in fluid communication with a multitude of selected systems that need fluid de-contamination from their associated processes.